Nasopharyngeal detection of atypical bacteria by multiplex polymerase chain reaction panel in acutely ill children was associated with an increased risk of pneumonia.

AIM: We aimed to assess whether detection of respiratory bacteria by multiplex polymerase chain reaction (PCR) testing associates with clinical outcomes in acutely ill children. METHODS: This cross-sectional study enrolled children under the age of 18 with a suspected respiratory infection treated in a paediatric emergency department of Oulu University Hospital, Finland from January 2015 through December 2015. Nasopharyngeal samples were routinely analysed for 16 respiratory viruses and later, after storage, analysed with a multiplex PCR panel for seven respiratory bacteria. RESULTS: At least one bacterial pathogen was detected in 600 out of the 1195 children (50%). The mean age was 3.3 (SD 3.7) years and 54% were boys. Atypical bacteria were associated with a risk of pneumonia (adjusted odds ratio [aOR] 14.1, 95% CI 3.98-50.1). Co-detection of rhinovirus with Streptococcus pneumoniae was not associated with risk of pneumonia (aOR 2.39, 95% CI 0.78-7.30). Detection of Streptococcus pneumoniae, Haemophilus influenzae or both was not associated with the risk of hospital admission or prescription of antibiotics. CONCLUSION: Nasopharyngeal detection of atypical bacteria in acutely ill children was associated with a markedly increased risk of pneumonia. The clinical utility of wide testing for other respiratory bacteria needs further evaluation.